Caption: Whole caterpillar skin, light micrograph. The blue structures, from left to right, are: the head, the true legs, the spiracles, the prolegs, and at far right the claspers. In deep yellow, radiating from the spiracles, is the tracheal system for bringing oxygen to the body tissues. The brown lines are hairs or setae. Two parts of the respiratory system can be seen through the skin, one on the caterpillar's right-hand side and one on its left-hand side. Each system has the eight spiracles (blue circles) connected to one another by a wide trachea, and other tracheae branching in all directions from each spiracle. Magnification: x14 when printed at 10 centimetres across.